Moving stairway



Dec. 12, 1939. s. G. MARGLES MOVING STAIRWAY Filed May 7, 1958 2 Sheets-Sheet 1 w 1 F I2 3 m G m,

SM 41% W INVENTOI? AT'VIORNEY Dec. 12, 1939.

S, G. MARGLES MOVING STAIRWAY Filed May 7, 1938 2 Sheets-Sheet 2 0 m cl 5M LJIM/KM Q ,NVENTOR BY I'm-"11w!!! ATTORNEY Patented Dec. 12 1939 MOVING s'rAmwAY Samuel Gustave Margles, Brooklyl'h'N. Y., as: signor to Otis Elevator Company, New York, N.IY., a corporation of New Jersey Application May7, 193s, Serial No. 206,528

.1 Claim. ,(ol. 198-16) The invention relates to moving stairways.

Present day moving Stairways comprise an endless series of steps driven'usually at the upper end of the stairway by means of power driven sprocket wheels through rumiing gear chains. The steps are provided with curved risers and with treads having a plurality of longitudinally extending cleats. Combplates. are provided at the ends of the stairway, the teeth of the combplates extending into the grooves between the tread cleats and being inclined upwardly therefrom to facilitate the exit of passengers from the stairway.

It has been the practice with these constructions to provide relatively wide combplate teeth and tread cleats, resulting in even wider slots between the tread cleats and combplate teeth. Also, the ends of the cleats facing the riser of the adjacent step have been bevelled back to minimize the clearance between the bottom of the cleat grooves and the riser when the steps are in step formation on the incline of the stairway. This -resultsin a V-shaped slot between the ends of the cleats of adjacent steps when the steps are in platform formation and about to pass beneath the combplate.

The object of the invention is to obviate any.

possibility of an article, such as an umbrella tip or a childs finger, being caught between the treads and the combplate as the steps pass beneath the combplate or between the bottom of the step groove and the adjacent riser as the transition from step to platform formation takes place. In carrying out the invention, narrow cleats are provided on the step treads and narrow teeth are provided on the combplate with minimum operating clearance between them. Narrow slots are provided-between the tread cleats and between' appended claim.

In the drawings:

Figure 1 is aside view of a step and combplate construction embodying the invention, illustrating the step in its cooperative relationship with the combplate and also illustrating the cooperative relationship of this step with its adjacent step both in platform and step formation;

Figure 2 is an enlarged fragmental detail taken along the line 2-2 of Figure 1, illustrating the cooperative relationship of the tread cleats and combplate teeth;

Figure 3 is a plan view of the same with partiof I the combplate broken away;

Figure 4 is a view in section taken along the line 4--4 of Figure 2; and

Figures 5 and 6 are enlarged details illustrating the manner of removably securing the tread plate to tothe step frame.

Referring to the drawings, each step comprises a step frame l6 mounted on step brackets ll, one

on each side of the stairway. Each step is provided on each side with a chain wheel l8, and 14 with a trailer wheel 20 mounted'on bracket ll. These wheels are arranged to run on tracks (not shown). 'Each step frame comprises a curved riser 24 and a tread portion 25. Upon the tread. portion is mounted a tread plate 26 provided with l. a plurality of longitudinally extending grooves 21 to form cleats Ml.- The cleats mesh with the .teeth 30 of the combplates 3| at the ends of the stairway.

In present day practice, the width of the cleats 25 is generally about three-eighths of an inch, while the width of the grooves between the cleats is approximately one-half inch. With such construction, the combplate teeth are usually approximately one-quarter inch in width, while the 80' width of the slots between the teeth is approximately five-eighths of an inch. In accordance with the invention, the tread cleats and combplate teeth are made muchnarrower, with the width of the slots between cleats and between combplate teeth less than the width of a finger -of a small child and not greater than flve-six- 1 teenths of an inch. In an arrangement which has been found satisfactory, the tread cleats are approximately three-thirty-seconds of an inch in 40 width and the combplate teeth are approximately one-sixteenth of an inch in width. The width of the grooves between tread cleats is approximately seven-thirty-seconds of an inch, while the width of the slots between the combplate teeth is approximately one-quarter of an inch. Although the depth of the slots between cleats may be varied, in the preferred construction these slots are made rather shallow. It has been found that this depth may be made approximately seven-thirty-seconds of an inch. With such depth, the clearance between the bottom of The tread plate is secured to the tread portion of the step frame as by screws 32. Sound deadening material 29 is preferably provided between the tread plate and the frame. The tread plate may be permanently secured or it may be secured in such way as to be readily removable from the outside of the stairway. In either event, it is desirable to maintain a substantially unbroken tread surface of the tread cleats. This may be accomplished in case of permanent tread plates by securing a tread insert to the top of each mounting screw so as to continue the contour of the tread plate at the point where it is secured to the step frame. In case of removable treads, which is the construction illustrated, the insert 33 is arranged with a slot 34 to receive the head 35 of the mounting screw 32. The screw extends into the threaded aperture of a strip 31 weld-ed to the bottom of the tread portion of the step frame. A slot 38 is provided in the tread plate to receive the insert and keep it from turning. The upper portion of this insert is provided with an elongated cleat portion 40 to provide a continuance of the tread cleats. This cleat portion is arranged with Vd ends as illustrated in Figure 3 to fit in V slots 4| in the cleats. The screw is free to turn in the insert, the head of the screw being arranged with cross slots 42 to permit the tread plate to be rigidly secured to the tread frame by tightening down on the screw by use of a spanner tool.

The combplate 3i is made up of a body portion 43 which is welded to side plates 44 secured to the stairway framework. The teeth 30 of the combplate are formed on a detachable nosing 46 which is secured to the body portion as by screws 41. This nosing may be arranged in several sections to facilitate replacement. In back of the nosing is a tread 48. This tread is detachably secured to the body portion of the comb for purposes of replacement.

Each of the side plates 44 of the comb is provided at the lower front end with a guide portion 50. Each guide portion is bevelled at the front and rear both on the side and bottom. The purpose of this arrangement is to insure the passage of the tread cleats between the combplate teeth as the step passes the combplate. The side bevels of the front ends of the guide portions for the direction in which the stairway is moving are for cooperation with the sides of the step tread while the bottom bevels are for cooperation with the top of portions 52 of the tread. The clearance between these guide portions and the tread is less than that between the teeth of the combplate and the tread cleats so as to obviate any possibility of jamming. Thus, in case any tendency exists toward misalignment of a step as it reaches the combplate, the tread plate is guided into proper cooperative relationship with the teeth of the combplate.

The ends 55 of the tread cleats of each step toward the riser of an adjacent step are made vertical throughout their heighth except for a slight rounding off at the top corner of the cleat. The curvature of the risers is such that they are substantially parallel to the path of movement of the top corner of the cleat of the adjacent step in its transition from step to platform formation. With shallow tread slots, the effect may be satisfactorily approximated by striking the riser curvature from the same center of curvature 56 as on present day construction, thereby rendering the construction suitable for replacement purposes as well as for new installations, This construction is facilitated by'reducing the distance from the bottomof the tread plate grooves to the top of the step frame. Operating clearance between the riser and the end of the tread of the adjacent step is provided by making the radius of curvature of the riser slightly less than the step pitch, 1. e., the distance between chain wheel axles.

With this arrangement, the cleats of the steps are maintained at a substantially constant minimum clearance from the riser of the adjacent step as the transition from step to platform formation is made, and the V groove is eliminated when the steps are in platform formation. The cleats of the adjacent step extend outward over the risers slightly to further minimize the clearance between tread cleats to provide a substantially continuous tread surface when the steps are in platform formation. With such arrangement the tread plate is bevelled back slightly for the purpose of operating clearance.

The tread plates may be made in sections if desired. Where the width of the step is such as to render it desirable to arrange the tread in two sections, to render one tread section suitable for both sides of the step, both ends of the sections are bevelled back. The tread plates are preferably zinc die-castings, while the sections of the combplate are preferably of stainless steel with the comb teeth formed by machining.

With the above construction, the narrow tread slots, the narrow combplate teeth slots and the vertical ends of the cleats obviate the possibility of an article or a person's finger being caught between the step and the combplate as the step treads enter the combplate at the exit end of the stairway, and the narrow tread slots obviate the possibility of such article or finger being inserted between the bottom of the tread slot and the riser of the adjacent step while the steps are in step formation or during their transition.

Although the invention has been described with reference to Figure 2 as applied to an ascending moving stairway, it is to be understood that it is equally applicable to descending stairways and to those which are reversible.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

In a moving stairway in which each step comprises a frame having a riser portion and a tread portion, a tread plate provided with a plurality of longitudinally extending cleats for meshing with the teeth of a combplate at the end of the stairway, means for removably securing said tread plate to said tread portion of one of said steps, said means comprising a screw extending into a threaded aperture in said step frame, said tread plate having a depression through a cleat to receive said screw, and an insert for said depression, said insert having a slot to receive the head of said screw and a cleat portion for forming a bridge between the ends of said cleat at said depression, said screw having cross slots to enable it to be secured to said frame.

SAMUEL GUSTAVE MARGLES. 

